The present invention relates to rotary recording medium reproducing apparatuses capable of placing and leaving a rotary recording medium in a state possible for reproduction within the rotary recording medium reproducing apparatus when a jacket (disc case) having a lid for accommodating the rotary recording medium therein is inserted into and then pulled out from within the rotary recording medium reproducing apparatus, and also capable of incasing the rotary recording medium within the jacket so that the rotary recording medium can be obtained outside the rotary recording medium reproducing apparatus together with the jacket, when the empty jacket is inserted into and then pulled out from within the reproducing apparatus. The present invention further and especially relates to the above type of a rotary recording medium reproducing apparatus having a rotary recording medium clamping mechanism for clamping the rotary recording medium accommodated within the jacket when the disc case is inserted into and then pulled out from within the reproducing apparatus.
Conventionally, in an apparatus for reproducing a rotary recording medium (referring to video disc, PCM audio disc, and the like, and hereinafter simply referred to as a disc), there are types of apparatuses in which a disc is reproduced when the disc is loaded upon holding and placing of the disc within the reproducing apparatus, by inserting into and then pulling out a disc case which has a lid and accommodates a disc therein, from within the reproducing apparatus.
As a conventional apparatus of this type, a reproducing apparatus was proposed in a U.S. patent application Ser. No. 231,868 filed Feb. 5, 1981, entitled "DISC-SHAPED RECORDING MEDIUM REPRODUCING APPARATUS" in which the assignee is the same as that of the present application. This previously proposed reproducing apparatus operates together with a disc case comprising a jacket which has a space for accommodating a disc and an opening for allowing the disc to go in and out of the jacket, and a lid member inserted through the opening of the jacket for closing the opening of the jacket, where the reproducing apparatus comprises an inserting opening through which the case is inserted, a turntable for rotating the disc, a disc clamping mechanism for clamping the disc provided at an innermost part on the opposite side from the inserting opening with respect to the turntable, lowering and raising means for lowering the disc to a position where the disc is placed on the turntable from a clamping position where the disc is clamped by the clamping mechanism upon starting of the reproduction and raising the disc to the clamping position from the turntable upon finishing or discontinuing of the reproduction, a reproducing transducer for reproducing and disc placed on the turntable, and moving means for moving the reproducing transducer from a waiting position to a reproducing position with respect to the disc.
In the above previously proposed reproducing apparatus, the disc clamping mechanism comprises a lower clamp arm which comes to be held horizontally upon clamping the disc, an upper clamp arm disposed to face the lower clamp arm, and a spring member which is forcibly deformed resiliently when the disc case is inserted to the innermost position inside the reproducing apparatus, thereby imparting a clamping force to the upper clamp arm, and is adapted to sandwich an outer peripheral groove guard of the disc between the upper and lower clamp arms due to a spring force thereby clamping the disc. In this disc clamping mechanism, since the spring member should be forced to undergo resilient deformation in response to insertion of the disc case into the reproducing apparatus, the operation for inserting the disc case to the final position inside the reproducing apparatus accompanies not only deterioration of tactile feeling of operation but also requirements of a large operational force for inserting the disc case into the reproducing apparatus. In a case where a larger spring member is employed to increase the clamping force, stronger operational force is required by that much. This gives rise to problems such that the disc case insertion operation may cause the reproducing apparatus to be pushed backwards undesirably, and that by ceasing insertion operation upon felt heavy, the jacket is erroneously pulled out before the disc case reaches the final position, which results in that the disc is not clamped normally.